Critical Buffer Overflow Vulnerability in libpq Package: Important Security Update Required
Summary
ALSA-2026:44308: Important: libpq security update. Affects libpq versions < 13.23-3.el9_8. Fixed in 13.23-3.el9_8. How to fix ↓
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Background
The libpq package is the PostgreSQL client library that enables client applications to connect to PostgreSQL servers. It is a crucial component for applications that rely on PostgreSQL for data management. The library provides a range of functionalities, including connection handling, query execution, and data retrieval. However, it has been identified to have a critical vulnerability that could allow unauthorized access and manipulation of client stack memory.
Vulnerability Detail
The vulnerability identified as CVE-2026-6477 is a buffer overflow issue within the PostgreSQL libpq library. This flaw allows a server superuser to overwrite the stack memory of a client application, potentially leading to arbitrary code execution or data corruption. The origin of this vulnerability lies in improper handling of input data, which can be exploited by an attacker with superuser privileges on the PostgreSQL server. The ramifications of this vulnerability are severe, as it could compromise the integrity and confidentiality of client applications connected to the database.
How To Fix
Minimum fixed version
13.23-3.el9_8
This is the first release that contains the fix.
sudo dnf update libpqTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider restricting superuser access on the PostgreSQL server to mitigate the risk of exploitation until the package can be updated. Additionally, ensure that all client applications are monitored for unusual behavior.
Conclusion
The libpq package has a critical vulnerability that requires immediate attention. By updating to the patched version, users can protect their applications from potential exploitation. It is crucial to stay informed about vulnerabilities and utilize tools like Vulert to monitor for any security risks in your software.
See every vulnerability recorded for libpq →
FAQ
CVE-2026-6477 is a buffer overflow vulnerability in the PostgreSQL libpq library that allows a server superuser to overwrite client stack memory.
You can check if your application is affected by using the Vulert playground at Vulert Scanner, which analyzes your manifest file for vulnerabilities.
The potential impacts include arbitrary code execution, data corruption, and unauthorized access to sensitive information within client applications.
Yes, a patch is available in version 13.23-3.el9_8 for both libpq and libpq-devel packages.
If immediate updates are not possible, restrict superuser access on the PostgreSQL server and monitor client applications for any suspicious activity.
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